def tan2fp(xtan, ytan):
"""
Convert tangent plane coordinates to focal plane mm
Args:
xtan: sin(theta)*cos(phi)
ytan: sin(theta)*sin(phi)
Returns xfp, yfp in CS5 coordinates on the focal plane
"""
phi = np.arctan2(ytan, xtan)
rtan = np.hypot(xtan, ytan)
theta = arcsind(rtan)
r = theta2radius(theta)
x = r * np.cos(phi)
y = r * np.sin(phi)
return x, y
def altaz2hadec(alt,az) :
"""
Convert Altitude, Azimuth to HA, Dec at Kitt Peak elevation
Args:
alt: float or 1D np.array altitude in degrees
az: float or 1D np.array azimuth in degrees
Returns: ha, dec
ha: float or 1D np.array Hour Angle in degrees
dec: float or 1D np.array Hour Angle in degrees
"""
salt,calt = sincosd(alt)
saz,caz = sincosd(az)
slat,clat = sincosd(LATITUDE)
ha = arctan2d( -saz*calt, -caz*slat*calt+salt*clat)
dec = arcsind(slat*salt+clat*calt*caz)
return ha,dec
def getLONLAT(xyz):
"""Convert xyz into its spherical angles"""
xyz = getNormalized(xyz) # usually unnecessary
return arctan2d(xyz[1],xyz[0]) , arcsind(xyz[2]) # degrees